Need Twitter help!

I signed up for a twitter after some of ma friends told me that its a good way for people get info about celebs and sports and all that.

So i go to the homepage and it has conversation things on the right side of the website. So i go the Penguins one cuz i was watching the stanley cup finals yesterday but i could not find out how to enter it. to enter the conversation do you have to follow the leader or somthing?